论文部分内容阅读
目的建立水中痕量铜的磁性固相萃取-火焰原子吸收法的检测方法。方法采用磁性固相萃取技术,水样经自制的Fe3O4/MWCNTs磁性纳米材料富集后用0.1 mol/L的HNO3洗脱,火焰原子吸收法进行定量分析。并对实验产生影响的一些参数如:样品的p H值、吸附时间、洗脱剂及其浓度、吸附剂的用量等进行了优化。结果本实验合成的Fe3O4/MWCNTs磁性纳米材料具有小的尺寸、大的比表面积、良好的分散性、较强的吸附能力等优点;具有顺磁性,在外加磁场的作用下易实现固液分离。在最佳实验条件下,铜在0.1μg/L~5μg/L时呈良好线性,并对1.0μg/L溶液进行平行测定11次,其相对标准偏差为2.3%。检出限为0.036μg/L,富集因子可达到100,并且吸附剂至少可以预富集/洗脱循环使用100次。结论该方法具有操作简单、灵敏度高、仪器简单、操作快速、污染小等优点。此方法应用于水样中铜离子含量的测定,得到令人满意的结果。
Objective To establish a magnetic solid phase extraction method for the determination of trace copper in water by flame atomic absorption spectrometry. Methods Magnetic solid-phase extraction (SPE-MS) was used. The water sample was enriched with homemade Fe3O4 / MWCNTs magnetic nanomaterials. The sample was eluted with 0.1 mol / L HNO3 and quantified by flame atomic absorption spectrometry. And some parameters that affect the experiment such as: sample p H value, adsorption time, eluent and its concentration, the amount of adsorbent and so on were optimized. Results The Fe3O4 / MWCNTs magnetic nanomaterials synthesized in this study have the advantages of small size, large specific surface area, good dispersibility and strong adsorption capacity. They have paramagnetic properties and are easy to realize solid-liquid separation under the action of applied magnetic field. Under the optimal experimental conditions, copper showed a good linearity at 0.1μg / L ~ 5μg / L, and the relative standard deviation of 2.3% was 1.0μg / L. The detection limit is 0.036μg / L, the enrichment factor can reach 100, and the adsorbent can be pre-enriched / eluted at least 100 cycles. Conclusion The method has the advantages of simple operation, high sensitivity, simple instrument, fast operation, small pollution and so on. This method is applied to the determination of copper ion content in water samples, with satisfactory results.